The invention concerns a machine for harvesting root crop, in particular in the form of a complete potato harvesting machine embodied as a self-propelled potato harvester or a stationary cleaning machine. Such a machine comprises a lifting device in the forward area of a machine frame, wherein downstream thereof in the conveying direction an ascending first sorting stretch is associated therewith that comprises a substantially unchangeable working width. With the sorting stretch, the admixtures can be sorted out in such a way that the crop in the form of root crop such as beets, potatoes or the like can be conveyed as a respective conveyed material across at least one cleaning stretch to a collecting bunker or an unloading elevator, wherein at least one conveying run movable along the sectionwise ascending sorting stretch is guided at least to a top drop zone and subsequently the respective conveyed material can be transferred onto at least one downstream conveying stretch.
Machines for harvesting and processing root crop, in particular potatoes, have been known for a long time in various embodiments of pull-behind devices or self-propelled machines. In such machine configurations, lifting devices that lift several rows of crop with admixtures from the soil of the field are used in connection with a downstream conveying and cleaning system. DE 32 35 087C2 discloses such a construction in connection with a root crop harvesting machine that is pulled by a tractor.
In a potato harvesting machine according to DE 93 20 575.9 U1, a screen conveyor with which the crop and the admixtures are supplied to the next cleaning stage is provided downstream of a lifting device that is provided with lifting shares.
A more complex configuration of a pulled potato harvesting machine according to DE 10 2007 034 44 6 A1 comprises also downstream of a lifting device the first longitudinal conveying device which is effective in combination with a second screen belt stage secured in the same frame construction is effective. In this context, downstream of a transfer zone provided with a belt overlap, an upward conveying of the mixture is provided. In this context, all of the conveying and cleaning component groups are secured on a substantially closed frame construction of the machine so that a linear movement to an upper deflection and sorting section is realized.
A similar construction is provided for a self-propelled complete potato harvesting machine (brochure “SF 150/170-60” of the company Grimme Landmaschinenfabrik GmbH & Co. KG, Damme, Germany, publication number L05.0851.DE04/08/2000; 2008) wherein a first cleaning unit that receives the crop and is provided with receiving belt and a first screen belt and a second cleaning unit with a second screen belt are arranged in linear sequence behind each other as conveying component groups.
In the technical further development of such harvesting machines for root crop, for improving the cleaning and sorting conditions, respective components of the conveying complex that are arranged downstream of the leading receiving and cleaning system or respective belt component groups that are provided for manual sorting, for example, in the area of transfer conveyor belts, are replaced with larger component groups that, in relation to the machine frame, may cause a lateral projection. This affects at the same time handling of the system that is to be steered along the contour of the field because performing a complete lifting process in particular near the respective edge zones of the field, may be affected by projecting components of the machine and crop loss can thus occur. In the aforementioned concept of the self-propelled complete potato harvesting machines according to the aforementioned brochure “SF 150/170-60”, the steering and drive unit is arranged upstream of the pickup system for the crop so that the corresponding length of the machine is considerable.
The object of the invention is to provide a machine for harvesting root crop, in particular in the form of a complete potato harvesting machine, which, with minimal technical expenditure, can also be used as a compact unit for more than two crop ridges, which with an optimizable lifting process enables an increase of the harvesting performance, and which in the area of the conveying and distribution component groups comprises an operating structure that is adjustable with regard to a travel width for traveling on roads.